#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>

int main(int argc,char **argv)
{
	int fd;
	int val = 1;
	fd = open("/dev/xyz",O_RDWR);
	if(fd<0)
		printf("can't open!\n");
	
	if(argc != 2)
	{
		printf("Usage:\n");
		printf("%s <on|off>\n",argv[0]);
		return 0;
	}
	if(strcmp(argv[1],"on")==0)
	{
		val = 1;
	}else{
		val = 0;
	}
	write(fd,&val,4);
	return 0;
}
